is the 1UZ Lower intake manifold restrictive?

[FoPar]

we don't think so. excellent power can be made using the lower intake manifold. we have discussed it with a few of the guys on www.v-eight.com and thought some people may find it of interest here as well. alot of people claim that the lower intake manifold restricts the ability of making power above 5500rpm, we thought we would give it a try and see what happened because we haven't got $1000's to spend on a whole new custom intake manifold. we re-tuned the car on the weekend with a bigger set of turbo exhaust housings because we believed it was the turbo housings choking power not the LM, the new housings allowed for better airflow and the power kept climbing all the way to 72-7500rpm. power and torque picked up thru the whole rev and boost range. @ 15psi there was a 50rwhp pickup from 570hp to 620hp.

we have a mild port job, $700 cutom plenum which still has the factory 1uz lower intake manifold. the lower manifold has just been port matched to fit the head.

E85 .63 rear tune and new 1.06 tune to compare


video of the run
http://www.youtube.com/watch?v=Z5VelCOiHJE

 

[JustenGT8]

LOL you post, i post

I'm still confused by that dyno sheet....the new setup is that much laggier? It still looks to me that if you lay those curves on each other power noses over about the same place?

 

[kc95sc400]

I think there are a few things considered fact about the 1uz that are only partially true.

Anytime I've had mine on the dyno the power was steady going up all the way to redline, about 6400rpm or so. Now that I have the Adaptronic I should put it on the dyno again to if going to 7000rpm is worth it or not.

KC